emacs-app must write /opt/local/share/emacs/site-lisp/subdirs.el if it is not present

[vishketan@…]

If emacs-app is the only emacs that is installed via macports then the /opt/local/share/emacs/site-lisp/subdirs.el file is not written. Therefore, any of the packages (e.g. emacs-w3m) which are installed under the site-lisp directory are not loaded.

During installation emacs-app must detect if the subdirs.el file is present and if not then write this file.

[ryandesign (Ryan Carsten Schmidt)]

Ports should not generally alter their behavior based on what other ports are installed. We have to take into consideration that the user may get a pre-built port from the buildbot. A port should either always install a file, or never do so, not vary this based on the user's environment. But perhaps there is an opportunity for the port to do something useful in a post-activate block.

[vishketan@…]

IMHO the clean thing is to ensure that an emacs meta-package is installed when one of emacs, emacs22, emacs-snapshot, emacs-app, or emacs-app-devel is installed. This meta package will write this subdirs.el file and set links to the appropriate emacs binaries. Once this is done other emacs goodies (e.g. org-mode, cedet, ecb etc) must be modified to depend on this meta-package rather than on individual emacs instances as is currently being done. IIRC this is the way distributions like debian do things.

[humem (humem)]

I modified site-start.el of emacs-app to append ${prefix}/share/emacs/site-lisp and its subdirectories to load-path, and committed in r96526.